Immigration reform: How likely is your senator to back the bill?

FILE  In this Jan. 28, 2013, file photo Sen. Marco Rubio, R-Fla., center,speaks at a Capitol Hill news conference with a bipartisan group of leading senators to announce their agreement on the principles of sweeping legislation to rewrite the nation's immigration laws. Eight senators meet in private several times a week, alternating between, from left, Sen. John McCains, R-Ariz., and Sen. Charles Schumers, D-N.Y., offices, and in a capital riven by partisanship and gridlock, they are determined to be the exception and actually get something done. This is immigration reform's " Gang of Eight". At right is Sen. Robert Menendez, D-N.J., The group includes Sen.s Lindsey Graham, RS.C., Dick Durbin, D-Ill., Jeff Flake, R-Ariz., and Michael Bennet, D-Colo., not shown here. (AP Photo/J. Scott Applewhite)

Immigration reform: How likely is your senator to back it?

Most senators have kept mum about the immigration reform bill, but those days are coming to an end.With a key Senate committee beginning markup of the bipartisan proposal this week, time is running out for supporters and opponents.Because of the routine use of the filibuster in the Senate, backers will need 60 votes to pass the bill. But they've also set a goal of getting as many as 70 votes in order to give the bill momentum as it heads …